Our goal is to elucidate both the reversible and irreversible morphological and biochemical changes the cells of the inner ear may undergo following injury by mechanical or chemical trauma, ischemia or hypoxia. Changes in the permeability of the cochlear duct following injury will also be studied. The ears of the experimental animals (guinea pigs and chinchillas) will be studied by light and electron microscopy or analyzed by ultramicrochemical techniques. Collaboration with Drs. Donald H. Eldredge and John H. Mills on electrophysiological and behavioral data from the same or similarly treated animals is also planned.